System and method for providing quality of service in a virtual adapter

ABSTRACT

A method, computer program product, and distributed data processing system for associating a quality of service level to one or more virtual I/O adapters or virtual resources that reside within a physical adapter and are associated with a virtual host is provided. Specifically, a mechanism by which a single physical I/O adapter associates one or more virtual I/O adapters or virtual resources to a quality of service level is provided.

RELATED APPLICATIONS

This application is related to commonly assigned and co-pending U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040178US1) entitled “Method, System and Program Product for Differentiating Between Virtual Hosts on Bus Transactions and Associating Allowable Memory Access for an Input/Output Adapter that Supports Virtualization”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040179US1) entitled “Virtualized I/O Adapter for a Multi-Processor Data Processing System”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040180US1) entitled “Virtualized Fibre Channel Adapter for a Multi-Processor Data Processing System”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040181US1) entitled “Interrupt Mechanism on an IO Adapter That Supports Virtualization”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040182US1) entitled “System and Method for Modification of Virtual Adapter Resources in a Logically Partitioned Data Processing System”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040183US1) entitled “Method, System, and Computer Program Product for Virtual Adapter Destruction on a Physical Adapter that Supports Virtual Adapters”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040184US1) entitled “System and Method of Virtual Resource Modification on a Physical Adapter that Supports Virtual Resources”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040185US1) entitled “System and Method for Destroying Virtual Resources in a Logically Partitioned Data Processing System”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040186US1) entitled “Association of Memory Access Through Protection Attributes that are Associated to an Access Control Level on a PCI Adapter that Supports Virtualization”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040187US1) entitled “Association of Host Translations that are Associated to an Access Control Level on a PCI Bridge that Supports Virtualization”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040507US1) entitled “Method, Apparatus, and Computer Program Product for Coordinating Error Reporting and Reset Utilizing an I/O Adapter that Supports Virtualization”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040552US1) entitled “Method and System for Fully Trusted Adapter Validation of Addresses Referenced in a Virtual Host Transfer Request”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040553US1) entitled “System, Method, and Computer Program Product for a Fully Trusted Adapter Validation of Incoming Memory Mapped I/O Operations on a Physical Adapter that Supports Virtual Adapters or Virtual Resources”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040554US1) entitled “System and Method for Host Initialization for an Adapter that Supports Virtualization”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040555US1) entitled “Data Processing System, Method, and Computer Program Product for Creation and Initialization of a Virtual Adapter on a Physical Adapter that Supports Virtual Adapter Level Virtualization”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040556US1) entitled “System and Method for Virtual Resource Initialization on a Physical Adapter that Supports Virtual Resources”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040557US1) entitled “Method and System for Native Virtualization on a Partially Trusted Adapter Using Adapter Bus, Device and Function Number for Identification”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040558US1) entitled “Native Virtualization on a Partially Trusted Adapter Using PCI Host Memory Mapped Input/Output Memory Address for Identification”; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040559US1) entitled “Native Virtualization on a Partially Trusted Adapter Using PCI Host Bus, Device, and Function Number for Identification; U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040560US1) entitled “System and Method for Virtual Adapter Resource Allocation”; and U.S. patent application Ser. No. ______ (Attorney Docket No. AUS920040562US1) entitled “System and Method for Managing Metrics Table per Virtual Port in a Logically Partitioned Data Processing System” all of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates generally to communication protocols between a host computer and an input/output (I/O) adapter. More specifically, the present invention provides an implementation for supporting differentiated quality of service levels on a physical I/O adapter that supports I/O virtualization. In particular, the present invention provides a mechanism by which a single physical I/O adapter, such as a PCI, PCI-X, or PCI-E adapter, can associate one or more virtual I/O adapters or virtual resources to a quality of service level.

2. Description of Related Art

Virtualization is the creation of substitutes for real resources. The substitutes have the same functions and external interfaces as their real counterparts, but differ in attributes such as size, performance, and cost. These substitutes are virtual resources and their users are usually unaware of the substitute's existence. Servers have used two basic approaches to virtualize system resources: partitioning and logical partitioning (LPAR) managers. Partitioning creates virtual servers as fractions of a physical server's resources, typically in coarse (e.g. physical) allocation units (e.g. a whole processor, along with its associated memory and I/O adapters). LPAR managers are software or firmware components that can virtualize all server resources with fine granularity (e.g. in small fractions that of a single physical resource).

In conventional systems, servers that support virtualization have two general options for handling I/O. The first option was to not allow a single physical I/O adapter to be shared between virtual servers. The second option was to add functionality into the LPAR manager, or another suitable intermediary, that provides the isolation necessary to permit multiple operating systems to share a single physical adapter.

The first option has several problems. One significant problem is that expensive adapters cannot be shared between virtual servers. If a virtual server only needs to use a fraction of an expensive adapter, an entire adapter would be dedicated to the server. As the number of virtual servers on the physical server increases, this leads to underutilization of the adapters and more importantly a more expensive solution, because each virtual server needs a physical adapter dedicated to it. For physical servers that support many virtual servers, another significant problem with this approach is that it requires many adapter slots, and the accompanying hardware (e.g., chips, connectors, cables, and the like) required to attach those adapters to the physical server.

Though the second option provides a mechanism for sharing adapters between virtual servers, that mechanism must be invoked and executed on every I/O transaction. The invocation and execution of the sharing mechanism by the LPAR manager or other intermediary on every I/O transaction degrades performance. It also leads to a more expensive solution, because the customer must purchase more hardware, either to make up for the cycles used to perform the sharing mechanism or, if the sharing mechanism is offloaded to an intermediary, for the intermediary hardware.

It would be advantageous to have an improved method, apparatus, and computer instructions for associating a quality of service level to one or more virtual I/O adapters or virtual resources that reside within a physical adapter, such as a PCI, PCI-X, or PCI-E adapter, and are associated with a virtual host. It would also be advantageous to have the mechanism apply for adapters that support memory mapped I/O interfaces, such as Ethernet NICs (Network Interface Controllers), FC (Fibre Channel) HBAs (Host Bus Adapters), pSCSI (parallel SCSI) HBAs, InfiniBand, TCP/IP Offload Engines, RDMA (Remote Direct Memory Access) enabled NICs (Network Interface Controllers), iSCSI adapters, iSER (iSCSI Extensions for RDMA) adapters, and the like.

SUMMARY OF THE INVENTION

The present invention provides a method, computer program product, and distributed data processing system for associating a quality of service level to one or more virtual I/O adapters or virtual resources that reside within a physical adapter, such as a PCI, PCI-X, or PCI-E adapter, and are associated with a virtual host. Specifically, the present invention is directed to a mechanism by which a single physical I/O Adapter, such as a PCI, PCI-X, or PCI-E adapter, can associate one or more virtual I/O adapters or virtual resources to a quality of service level. Quality of service differentiation is provided to system images by associating quality of service level weights to system images allocated in a logically partitioned data processing system. Trusted software, such as a hypervisor, assigns quality of service level weights to sets of processing queues that are allocated to a system image. Thus, quality of service differentiation is provided on a per-system image basis by providing processing precedence to system images with higher quality of service level weights relative to other system images with lower quality of service level weights. Additionally, each system image assigns quality of service level weights to the processing queues that have been assigned to that system image. Thereby, quality of service differentiation is provided on a per-processing queue basis by providing processing precedence to processing queues with higher quality of service level weights relative to processing queues with lower quality of service level weights.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a diagram of a distributed computer system illustrated in accordance with a preferred embodiment of the present invention;

FIG. 2 is a functional block diagram of a small host processor node in accordance with a preferred embodiment of the present invention;

FIG. 3 is a functional block diagram of a small integrated host processor node in accordance with a preferred embodiment of the present invention;

FIG. 4 is a functional block diagram of a large host processor node in accordance with a preferred embodiment of the present invention;

FIG. 5 is a diagram illustrating the elements of the parallel Peripheral Computer Interface (PCI) bus protocol in accordance with a preferred embodiment of the present invention;

FIG. 6 is a diagram illustrating the elements of the serial PCI bus protocol (PCI-Express or PCI-E) in accordance with a preferred embodiment of the present invention;

FIG. 7 is a diagram illustrating I/O virtualization functions provided in a host processor node in order to provide virtual host access isolation in accordance with a preferred embodiment of the present invention;

FIG. 8 is a diagram illustrating the control fields used in a PCI bus transaction to identify a virtual adapter or system image in accordance with a preferred embodiment of the present invention;

FIG. 9 is a diagram illustrating adapter resources that must be virtualized in order to allow: an adapter to directly access virtual host resources; allow a virtual host to directly access Adapter resources; and allow a non-PCI port on the adapter to access resources on the adapter or host in accordance with a preferred embodiment of the present invention;

FIG. 10 is a diagram illustrating the creation of three access control levels used to manage a PCI family adapter that supports I/O virtualization in accordance with a preferred embodiment of the present invention;

FIG. 11 is a diagram illustrating how host memory that is associated with a system image is made available to a virtual adapter that is associated with that system image through the logical partitioning manager in accordance with a preferred embodiment of the present invention;

FIG. 12 is a diagram illustrating how a PCI family adapter allows a logical partitioning manager to associate memory in the PCI adapter to a system image and its associated virtual adapter in accordance with a preferred embodiment of the present invention;

FIG. 13 is a diagram illustrating one of the options for determining the virtual adapter that is associated with an incoming memory address in accordance with a preferred embodiment of the present invention;

FIG. 14 is a diagram illustrating one of the options for determining a virtual adapter that is associated with a PCI-X or PCI-E bus transaction in accordance with a preferred embodiment of the present invention;

FIG. 15 is a diagram illustrating a virtual adapter management approach for virtualizing adapter resources in accordance with a preferred embodiment of the present invention;

FIG. 16 is a diagram illustrating a virtual resource management approach for virtualizing adapter resources in accordance with a preferred embodiment of the present invention;

FIG. 17 is a diagrammatic illustration of quality of service resources used by a host and adapter to associate a quality of service level to one or more virtual I/O adapters or virtual resources that reside within a physical adapter in accordance with a preferred embodiment of the present invention;

FIG. 18 is a flowchart outlining an exemplary operation of the association of a quality of service level to one or more system images and its associated virtual I/O adapters or virtual resources that reside within a physical adapter in accordance with a preferred embodiment of the present invention;

FIG. 19 is a flowchart outlining an exemplary operation of the association of a quality of service level to one or more virtual resources owned by a system image and residing within a physical adapter in accordance with a preferred embodiment of the present invention; and

FIG. 20 is a flowchart outlining an exemplary operation of outbound transfers that use quality of service level differentiation of virtual I/O adapters or virtual resources that reside within a physical adapter in accordance with a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention applies to any general or special purpose host that uses a PCI family I/O adapter to directly attach a storage device or to attach to a network, where the network consists of endnodes, switches, routers and the links interconnecting these components. The network links can be, for example, Fibre Channel, Ethernet, InfiniBand, Advanced Switching Interconnect, or a proprietary link that uses proprietary or standard protocols. While embodiments of the present invention are shown and described as employing a peripheral component interconnect (PCI) family adapter, implementations of the invention are not limited to such a configuration as will be apparent to those skilled in the art. Teachings of the invention may be implemented on any physical adapter that support a memory mapped input/output (MMIO) interface, such as, but not limited to, HyperTransport, Rapid I/O, proprietary MMIO interfaces, or other adapters having a MMIO interface now know or later developed. Implementations of the present invention utilizing a PCI family adapter are provided for illustrative purposes to facilitate an understanding of the invention.

With reference now to the figures and in particular with reference to FIG. 1, a diagram of a distributed computer system is illustrated in accordance with a preferred embodiment of the present invention. The distributed computer system represented in FIG. 1 takes the form of a network, such as network 120, and is provided merely for illustrative purposes and the embodiments of the present invention described below can be implemented on computer systems of numerous other types and configurations. Two switches (or routers) are shown inside of network 120—switch 116 and switch 140. Switch 116 connects to small host node 100 through port 112. Small host node 100 also contains a second type of port 104 which connects to a direct attached storage subsystem, such as direct attached storage 108.

Network 120 can also attach large host node 124 through port 136 which attaches to switch 140. Large host node 124 can also contain a second type of port 128, which connects to a direct attached storage subsystem, such as direct attached storage 132.

Network 120 can also attach a small integrated host node 144 which is connected to network 120 through port 148 which attaches to switch 140. Small integrated host node 144 can also contain a second type of port 152 which connects to a direct attached storage subsystem, such as direct attached storage 156.

Turning next to FIG. 2, a functional block diagram of a small host node is depicted in accordance with a preferred embodiment of the present invention. Small host node 202 is an example of a host processor node, such as small host node 100 shown in FIG. 1.

In this example, small host node 202 includes two processor I/O hierarchies, such as processor I/O hierarchies 200 and 203, which are interconnected through link 201. In the illustrative example of FIG. 2, processor I/O hierarchy 200 includes processor chip 207 which includes one or more processors and their associated caches. Processor chip 207 is connected to memory 212 through link 208. One of the links on processor chip, such as link 220, connects to PCI family I/O bridge 228. PCI family I/O bridge 228 has one or more PCI family (e.g., PCI, PCI-X, PCI-Express, or any future generation of PCI) links that is used to connect other PCI family I/O bridges or a PCI family I/O adapter, such as PCI family adapter 244 and PCI family adapter 245, through a PCI link, such as links 232, 236, and 240. PCI family adapter 245 can also be used to connect a network, such as network 264, through a link via either a switch or router, such as switch or router 260. PCI family adapter 244 can be used to connect direct attached storage, such as direct attached storage 252, through link 248. Processor I/O hierarchy 203 may be configured in a manner similar to that shown and described with reference to processor I/O hierarchy 200.

With reference now to FIG. 3, a functional block diagram of a small integrated host node is depicted in accordance with a preferred embodiment of the present invention. Small integrated host node 302 is an example of a host processor node, such as small integrated host node 144 shown in FIG. 1.

In this example, small integrated host node 302 includes two processor I/O hierarchies 300 and 303, which are interconnected through link 301. In the illustrative example, processor I/O hierarchy 300 includes processor chip 304, which is representative of one or more processors and associated caches. Processor chip 304 is connected to memory 312 through link 308. One of the links on the processor chip, such as link 330, connects to a PCI family adapter, such as PCI family adapter 345. Processor chip 304 has one or more PCI family (e.g., PCI, PCI-X, PCI-Express, or any future generation of PCI) links that is used to connect either PCI family I/O bridges or a PCI family I/O adapter, such as PCI family adapter 344 and PCI family adapter 345 through a PCI link, such as links 316, 330, and 324. PCI family adapter 345 can also be used to connect with a network, such as network 364, through link 356 via either a switch or router, such as switch or router 360. PCI family adapter 344 can be used to connect with direct attached storage 352 through link 348.

Turning now to FIG. 4, a functional block diagram of a large host node is depicted in accordance with a preferred embodiment of the present invention. Large host node 402 is an example of a host processor node, such as large host node 124 shown in FIG. 1.

In this example, large host node 402 includes two processor I/O hierarchies 400 and 403 interconnected through link 401. In the illustrative example of FIG. 4, processor I/O hierarchy 400 includes processor chip 404, which is representative of one or more processors and associated caches. Processor chip 404 is connected to memory 412 through link 408. One of the links, such as link 440, on the processor chip connects to a PCI family I/O hub, such as PCI family I/O hub 441. The PCI family I/O hub uses a network 442 to attach to a PCI family I/O bridge 448. That is, PCI family I/O bridge 448 is connected to switch or router 436 through link 432 and switch or router 436 also attaches to PCI family I/O hub 441 through link 443. Network 442 allows the PCI family I/O hub and PCI family I/O bridge to be placed in different packages. PCI family I/O bridge 448 has one or more PCI family (e.g., PCI, PCI-X, PCI-Express, or any future generation of PCI) links that is used to connect with other PCI family I/O bridges or a PCI family I/O adapter, such as PCI family adapter 456 and PCI family adapter 457 through a PCI link, such as links 444, 446, and 452. PCI family adapter 456 can be used to connect direct attached storage 476 through link 460. PCI family adapter 457 can also be used to connect with network 464 through link 468 via, for example, either a switch or router 472.

Turning next to FIG. 5, illustrations of the phases contained in a PCI bus transaction 500 and a PCI-X bus transaction 520 are depicted in accordance with a preferred embodiment of the present invention. PCI bus transaction 500 depicts a conventional PCI bus transaction that forms the unit of information which is transferred through a PCI fabric for conventional PCI. PCI-X bus transaction 520 depicts the PCI-X bus transaction that forms the unit of information which is transferred through a PCI fabric for PCI-X.

PCI bus transaction 500 shows three phases: an address phase 508; a data phase 512; and a turnaround cycle 516. Also depicted is the arbitration for next transfer 504, which can occur simultaneously with the address, data, and turnaround cycle phases. For PCI, the address contained in the address phase is used to route a bus transaction from the adapter to the host and from the host to the adapter.

PCI-X transaction 520 shows five phases: an address phase 528; an attribute phase 532; a response phase 560; a data phase 564; and a turnaround cycle 566. Also depicted is the arbitration for next transfer 524 which can occur simultaneously with the address, attribute, response, data, and turnaround cycle phases. Similar to conventional PCI, PCI-X uses the address contained in the address phase to route a bus transaction from the adapter to the host and from the host to the adapter. However, PCI-X adds the attribute phase 532 which contains three fields that define the bus transaction requester, namely: requester bus number 544, requester device number 548, and requester function number 552 (collectively referred to herein as a BDF). The bus transaction also contains a tag 540 that uniquely identifies the specific bus transaction in relation to other bus transactions that are outstanding between the requester and a responder. The byte count 556 contains a count of the number of bytes being sent.

Turning now to FIG. 6, an illustration of the phases contained in a PCI-Express bus transaction is depicted in accordance with a preferred embodiment of the present invention. PCI-E bus transaction 600 forms the unit of information which is transferred through a PCI fabric for PCI-E.

PCI-E bus transaction 600 shows six phases: frame phase 608; sequence number 612; header 664; data phase 668; cyclical redundancy check (CRC) 672; and frame phase 680. PCI-E header 664 contains a set of fields defined in the PCI-Express specification. The requestor identifier (ID) field 628 contains three fields that define the bus transaction requester, namely: requestor bus number 684, requestor device number 688, and requester function number 692. The PCI-E header also contains tag 652, which uniquely identifies the specific bus transaction in relation to other bus transactions that are outstanding between the requestor and a responder. The length field 644 contains a count of the number of bytes being sent.

With reference now to FIG. 7, a functional block diagram of a PCI adapter, such as PCI family adapter 736, and the firmware and software that run on host hardware (e.g. processor with possibly an I/O hub or I/O bridge), such as host hardware 700, is depicted in accordance with a preferred embodiment of the present invention.

FIG. 7 also shows a logical partitioning (LPAR) manager 708 running on host hardware 700. LPAR manager 708 may be implemented as a Hypervisor manufactured by International Business Machines, Inc. of Armonk, N.Y. LPAR manager 708 can run in firmware, software, or a combination of the two. LPAR manager 708 hosts two system image (SI) partitions, such as system image 712 and system image 724 (illustratively designated system image 1 and system image 02, respectively). The system image partitions may be respective operating systems running in software, a special purpose image running in software, such as a storage block server or storage file server image, or a special purpose image running in firmware. Applications can run on these system images, such as applications 716, 720, 728, and 732 (illustratively designated application 1A, application 2, application 1B and application 3). Applications 716 and 728 are representative of separate instances of a common application program, and are thus illustratively designated with respective references of “1A” and “1B”. In the illustrative example, applications 716 and 720 run on system image 712 and applications 728 and 732 run on system image 724. As referred to herein, a virtual host comprises a system image, such as system image 712, or the combination of a system image and applications running within the system image. Thus, two virtual hosts are depicted in FIG. 7.

PCI family adapter 736 contains a set of physical adapter configuration resources 740 and physical adapter memory resources 744. The physical adapter configuration resources 740 and physical adapter memory resources 744 contain information describing the number of virtual adapters that PCI family adapter 736 can support and the physical resources allocated to each virtual adapter. As referred to herein, a virtual adapter is an allocation of a subset of physical adapter resources and virtualized resources such as a subset of physical adapter resources and physical adapter memory, that is associated with a logical partition, such as system image 712 and applications 716 and 720 running on system image 712, as described more fully hereinbelow. LPAR manager 708 is provided a physical configuration resource interface 738, and physical memory configuration interface 742 to read and write into the physical adapter configuration resource and memory spaces during the adapter's initial configuration and reconfiguration. Through the physical configuration resource interface 738 and physical configuration memory interface 742, LPAR manager 708 creates virtual adapters and assigns physical resources to each virtual adapter. LPAR manager 708 may use one of the system images, for example a special software or firmware partition, as a hosting partition that uses physical configuration resource interface 738 and physical configuration memory interface 742 to perform a portion, or even all, of the virtual adapter initial configuration and reconfiguration functions.

FIG. 7 shows a configuration of PCI family adapter 736 configured with two virtual adapters. A first virtual adapter (designated virtual adapter 1) comprises virtual adapter resources 748 and virtual adapter memory 752 that were assigned by LPAR manager 708 and that is associated with system image 712 (designated system image 1). Similarly, a second virtual adapter (designated virtual adapter 2) comprises virtual adapter resources 756 and virtual adapter memory 760 that were assigned by LPAR manager 708 to virtual adapter 2 and that is associated with another system image 724 (designated system image 2). For an adapter used to connect to a direct attached storage, such as direct attached storage 108, 132, or 156 shown in FIG. 1, examples of virtual adapter resources may include: the list of the associated physical disks, a list of the associated logical unit numbers, and a list of the associated adapter functions (e.g., redundant arrays of inexpensive disks (RAID) level). For an adapter used to connect to a network, such as network 120 of FIG. 1, examples of virtual adapter resources may include: a list of the associated link level identifiers, a list of the associated network level identifiers, a list of the associated virtual fabric identifiers (e.g. Virtual LAN IDs for Ethernet fabrics, N-port IDs for Fibre Channel fabrics, and partition keys for InfiniBand fabrics), and a list of the associated network layers functions (e.g. network offload services).

After LPAR manager 708 configures the PCI family adapter 736, each system image is allowed to only communicate with the virtual adapters that were associated with that system image by LPAR manager 708. As shown in FIG. 7 (by solid lines), system image 712 is allowed to directly communicate with virtual adapter resources 748 and virtual adapter memory 752 of virtual adapter 1. System image 712 is not allowed to directly communicate with virtual adapter resources 756 and virtual adapter memory 760 of virtual adapter 2 as shown in FIG. 7 by dashed lines. Similarly, system image 724 is allowed to directly communicate with virtual adapter resources 756 and virtual adapter memory 760 of virtual adapter 2, and is not allowed to directly communicate with virtual adapter resources 748 and virtual adapter memory 752 of virtual adapter 1.

With reference now to FIG. 8, a depiction of a component, such as a processor, I/O hub, or I/O bridge 800, inside a host node, such as small host node 100, large host node 124, or small, integrated host node 144 shown in FIG. 1, that attaches a PCI family adapter, such as PCI family adapter 804, through a PCI-X or PCI-E link, such as PCI-X or PCI-E Link 808, in accordance with a preferred embodiment of the present invention is shown.

FIG. 8 shows that when a system image, such as system image 712 or 724, or LPAR manager 708 shown in FIG. 7 performs a PCI-X or PCI-E bus transaction, such as host to adapter PCI-X or PCI-E bus transaction 812, the processor, I/O hub, or I/O bridge 800 that connects to the PCI-X or PCI-E link 808 which issues the host to adapter PCI-X or PCI-E bus transaction 812 fills in the bus number, device number, and function number fields in the PCI-X or PCI-E bus transaction. The processor, I/O hub, or I/O bridge 800 has two options for how to fill in these three fields: it can either use the same bus number, device number, and function number for all software components that use the processor, I/O hub, or I/O bridge 800; or it can use a different bus number, device number, and function number for each software component that uses the processor, I/O hub, or I/O bridge 800. The originator or initiator of the transaction may be a software component, such as system image 712 or system image 724 (or an application running on a system image), or LPAR manager 708.

If the processor, I/O hub, or I/O bridge 800 uses the same bus number, device number, and function number for all transaction initiators, then when a software component initiates a PCI-X or PCI-E bus transaction, such as host to adapter PCI-X or PCI-E bus transaction 812, the processor, I/O hub, or I/O bridge 800 places the processor, I/O hub, or I/O bridge's bus number in the PCI-X or PCI-E bus transaction's requestor bus number field 820, such as requester bus number 544 field of the PCI-X transaction shown in FIG. 5 or requestor bus number 684 field of the PCI-E transaction shown in FIG. 6. Similarly, the processor, I/O hub, or I/O bridge 800 places the processor, I/O hub, or I/O bridge's device number in the PCI-X or PCI-E bus transaction's requester device number 824 field, such as requester device number 548 field shown in FIG. 5 or requestor device number 688 field shown in FIG. 6. Finally, the processor, I/O hub, or I/O bridge 800 places the processor, I/O hub, or I/O bridge's function number in the PCI-X or PCI-E bus transaction's requestor function number 828 field, such as requestor function number 552 field shown in FIG. 5 or requester function number 692 field shown in FIG. 6. The processor, I/O hub, or I/O bridge 800 also places in the PCI-X or PCI-E bus transaction the physical or virtual adapter memory address to which the transaction is targeted as shown by adapter resource or address 816 field in FIG. 8.

If the processor, I/O hub, or I/O bridge 800 uses a different bus number, device number, and function number for each transaction initiator, then the processor, I/O hub, or I/O bridge 800 assigns a bus number, device number, and function number to the transaction initiator. When a software component initiates a PCI-X or PCI-E bus transaction, such as host to adapter PCI-X or PCI-E bus transaction 812, the processor, I/O hub, or I/O bridge 800 places the software component's bus number in the PCI-X or PCI-E bus transaction's requester bus number 820 field, such as requestor bus number 544 field shown in FIG. 5 or requester bus number 684 field shown in FIG. 6. Similarly, the processor, I/O hub, or I/O bridge 800 places the software component's device number in the PCI-X or PCI-E bus transaction's requestor device number 824 field, such as requestor device number 548 field shown in FIG. 5 or requester device number 688 field shown in FIG. 6. Finally, the processor, I/O hub, or I/O bridge 800 places the software component's function number in the PCI-X or PCI-E bus transaction's requester function number 828 field, such as requester function number 552 field shown in FIG. 5 or requester function number 692 field shown in FIG. 6. The processor, I/O hub, or I/O bridge 800 also places in the PCI-X or PCI-E bus transaction the physical or virtual adapter memory address to which the transaction is targeted as shown by adapter resource or address field 816 in FIG. 8.

FIG. 8 also shows that when physical or virtual adapter 806 performs PCI-X or PCI-E bus transactions, such as adapter to host PCI-X or PCI-E bus transaction 832, the PCI family adapter, such as PCI physical family adapter 804, that connects to PCI-X or PCI-E link 808 which issues the adapter to host PCI-X or PCI-E bus transaction 832 places the bus number, device number, and function number associated with the physical or virtual adapter that initiated the bus transaction in the requestor bus number, device number, and function number 836, 840, and 844 fields. Notably, to support more than one bus or device number, PCI family adapter 804 must support one or more internal busses (For a PCI-X adapter, see the PCI-X Addendum to the PCI Local Bus Specification Revision 1.0 or 1.0a; for a PCI-E adapter see PCI-Express Base Specification Revision 1.0 or 1.0a the details of which are herein incorporated by reference). To perform this function, LPAR manager 708 associates each physical or virtual adapter to a software component running by assigning a bus number, device number, and function number to the physical or virtual adapter. When the physical or virtual adapter initiates an adapter to host PCI-X or PCI-E bus transaction, PCI family adapter 804 places the physical or virtual adapter's bus number in the PCI-X or PCI-E bus transaction's requester bus number 836 field, such as requestor bus number 544 field shown in FIG. 5 or requestor bus number 684 field shown in FIG. 6 (shown in FIG. 8 as adapter bus number 836). Similarly, PCI family adapter 804 places the physical or virtual adapter's device number in the PCI-X or PCI-E bus transaction's requestor device number 840 field, such as Requestor device Number 548 field shown in FIG. 5 or requester device number 688 field shown in FIG. 6 (shown in FIG. 8 as adapter device number 840). PCI family adapter 804 places the physical or virtual adapter's function number in the PCI-X or PCI-E bus transaction's requester function number 844 field, such as requestor function number 552 field shown in FIG. 5 or requester function number 692 field shown in FIG. 6 (shown in FIG. 8 as adapter function number 844). Finally, PCI family adapter 804 also places in the PCI-X or PCI-E bus transaction the memory address of the software component that is associated, and targeted by, the physical or virtual adapter in host resource or address 848 field.

With reference now to FIG. 9, a functional block diagram of a PCI adapter with two virtual adapters depicted in accordance with a preferred embodiment of the present invention is shown. Exemplary PCI family adapter 900 is configured with two virtual adapters 916 and 920 (illustratively designated virtual adapter 1 and virtual adapter 2). PCI family adapter 900 may contain one (or more) PCI family adapter ports (also referred to herein as an upstream port), such as PCI-X or PCI-E adapter port 912 that interface with a host system, such as small host node 100, large host node 124, or small integrated host node 144 shown in FIG. 1. PCI family adapter 900 may also contain one (or more) device or network ports (also referred to herein as downstream ports), such as physical port 904 and physical port 908 that interface with a peripheral or network device.

FIG. 9 also shows the types of resources that can be virtualized on a PCI adapter. The resources of PCI family adapter 900 that may be virtualized include processing queues, address and configuration memory, adapter PCI ports, host memory management resources and downstream physical ports, such as device or network ports. In the illustrative example, virtualized resources of PCI family adapter 900 allocated to virtual adapter 916 include, for example, processing queues 924, address and configuration memory 928, PCI virtual port 936 that is a virtualization of adapter PCI port 912, host memory management resources 984 (such as memory region registration and memory window binding resources on InfiniBand or iWARP), and virtual device or network ports, such as virtual external port 932 and virtual external port 934 that are virtualizations of physical ports 904 and 908. PCI virtual ports and virtual device and network ports are also referred to herein simply as virtual ports. Similarly, virtualized resources of PCI family adapter 900 allocated to virtual adapter 920 include, for example, processing queues 940, address and configuration memory 944, PCI virtual port 952 that is a virtualization of adapter PCI port 912, host memory management resources 980, and virtual device or network ports, such as virtual external port 948 and virtual external port 950 that are respectively virtualizations of respective physical ports 904 and 908.

Turning next to FIG. 10, a functional block diagram of the access control levels on a PCI family adapter, such as PCI family adapter 900 shown in FIG. 9, is depicted in accordance with a preferred embodiment of the present invention. The three levels of access are a super-privileged physical resource allocation level 1000, a privileged virtual resource allocation level 1008, and a non-privileged level 1016.

The functions performed at the super-privileged physical resource allocation level 1000 include but are not limited to: PCI family adapter queries, creation, modification and deletion of virtual adapters, submission and retrieval of work, reset and recovery of the physical adapter, and allocation of physical resources to a virtual adapter instance. The PCI family adapter queries are used to determine, for example, the physical adapter type (e.g. Fibre Channel, Ethernet, iSCSI, parallel SCSI), the functions supported on the physical adapter, and the number of virtual adapters supported by the PCI family adapter. The LPAR manager, such as LPAR manager 708 shown in FIG. 7, performs the physical adapter resource management 1004 functions associated with super-privileged physical resource allocation level 1000. However, the LPAR manager may use a system image, for example an I/O hosting partition, to perform the physical adapter resource management 1004 functions.

The functions performed at the privileged virtual resource allocation level 1008 include, for example, virtual adapter queries, allocation and initialization of virtual adapter resources, reset and recovery of virtual adapter resources, submission and retrieval of work through virtual adapter resources, and, for virtual adapters that support offload services, allocation and assignment of virtual adapter resources to a middleware process or thread instance. The virtual adapter queries are used to determine: the virtual adapter type (e.g. Fibre Channel, Ethernet, iSCSI, parallel SCSI) and the functions supported on the virtual adapter. A system image, such as system image 712 shown in FIG. 7, performs the privileged virtual adapter resource management 1012 functions associated with virtual resource allocation level 1008.

Finally, the functions performed at the non-privileged level 1016 include, for example, query of virtual adapter resources that have been assigned to software running at the non-privileged level 1016 and submission and retrieval of work through virtual adapter resources that have been assigned to software running at the non-privileged level 1016. An application, such as application 716 shown in FIG. 7, performs the virtual adapter access library 1020 functions associated with non-privileged level 1016.

Turning next to FIG. 11, a functional block diagram of host memory addresses that are made accessible to a PCI family adapter is depicted in accordance with a preferred embodiment of the present invention. PCI family adapter 1101 is an example of PCI family adapter 900 that may have virtualized resources as described above in FIG. 9.

FIG. 11 depicts four different mechanisms by which a LPAR manager 708 can associate host memory to a system image and to a virtual adapter. Once host memory has been associated with a system image and a virtual adapter, the virtual adapter can then perform DMA write and read operations directly to the host memory. System images 1108 and 1116 are examples of system images, such as system images 712 and 724 described above with reference to FIG. 7, that are respectively associated with virtual adapters 1104 and 1112. Virtual adapters 1104 and 1112 are examples of virtual adapters, such as virtual adapters 916 and 920 described above with reference to FIG. 9, that comprise respective allocations of virtual adapter resources and virtual adapter memory.

The first exemplary mechanism that LPAR manager 708 can use to associate and make available host memory to a system image and to one or more virtual adapters is to write into the virtual adapter's resources a system image association list 1122. Virtual adapter resources 1120 contains a list of PCI bus addresses, where each PCI bus address in the list is associated by the platform hardware to the starting address of a system image (SI) page, such as SI 1 page 1 1128 through SI 1 page N 1136 allocated to system image 1108. Virtual adapter resources 1120 also contains the page size, which is equal for all the pages in the list. At initial configuration, and during reconfigurations, LPAR manager 708 loads system image association list 1122 into virtual adapter resources 1120. The system image association list 1122 defines the set of addresses that virtual adapter 1104 can use in DMA write and read operations. After the system image association list 1122 has been created, virtual adapter 1104 must validate that each DMA write or DMA read requested by system image 1108 is contained within a page in the system image association list 1122. If the DMA write or DMA read requested by system image 1108 is contained within a page in the system image association list 1122, then virtual adapter 1104 may perform the operation. Otherwise virtual adapter 1104 is prohibited from performing the operation. Alternatively, the PCI family adapter 1101 may use a special, LPAR manager-style virtual adapter (rather than virtual adapter 1104) to perform the check that determines if a DMA write or DMA read requested by system image 1108 is contained within a page in the system image association list 1122. In a similar manner, virtual adapter 1112 associated with system image 1116 validates DMA write or read requests submitted by system image 1116. Particularly, virtual adapter 1112 provides validation for DMA read and write requests from system image 1116 by determining whether the DMA write or read request is in a page in system image association list (configured in a manner similarly to system image association list 1122) associated with system image pages of system image 1116.

The second mechanism that LPAR manager 708 can use to associate and make available host memory to a system image and to one or more virtual adapters is to write a starting page address and page size into system image association list 1122 in the virtual adapter's resources. For example, virtual adapter resources 1120 may contain a single PCI bus address that is associated by the platform hardware to the starting address of a system image page, such as SI 1 Page 1 1128. System image association list 1122 in virtual adapter resources 1120 also contains the size of the page. At initial configuration, and during reconfigurations, LPAR manager 708 loads the page size and starting page address into system image association list 1122 into the virtual adapter resources 1120. The system image association list 1122 defines the set of addresses that virtual adapter 1104 can use in DMA write and read operations. After the system image association list 1122 has been created, virtual adapter 1104 validates whether each DMA write or DMA read requested by system image 1108 is contained within a page in system image association list 1122. If the DMA write or DMA read requested by system image 1108 is contained within a page in the system image association list 1122, then virtual adapter 1104 may perform the operation. Otherwise, virtual adapter 1104 is prohibited from performing the operation. Alternatively, the PCI family adapter 1101 may use a special, LPAR manager-style virtual adapter (rather than virtual adapter 1104) to perform the check that determines if a DMA write or DMA read requested by system image 1108 is contained within a page in the system image association list 1122. In a similar manner, virtual adapter 1112 associated with system image 1116 may validate DMA write or read requests submitted by system image 1116. Particularly, a system image association list similar to system image association list 1122 may be associated with virtual adapter 1112. The system image association list associated with virtual adapter 1112 is loaded with a page size and starting page address of a system image page of system image 1116 associated with virtual adapter 1112. The system image association list associated with virtual adapter 1112 thus provides a mechanism for validation of DMA read and write requests from system image 1116 by determining whether the DMA write or read request is in a page in a system image association list associated with system image pages of system image 1116.

The third mechanism that LPAR manager 708 can use to associate and make available host memory to a system image and to one or more virtual adapters is to write into the virtual adapter's resources a system image buffer association list 1154. In FIG. 11, virtual adapter resources 1150 contains a list of PCI bus address pairs (starting and ending address), where each pair of PCI bus addresses in the list is associated by the platform hardware to a pair (starting and ending) of addresses of a system image buffer, such as SI 2 Buffer 1 1166 through SI 2 Buffer N 1180 allocated to system image 1116. At initial configuration, and during reconfigurations, LPAR manager 708 loads system image buffer association list 1154 into the virtual adapter resources 1150. The system image buffer association list 1154 defines the set of addresses that virtual adapter 1112 can use in DMA write and read operations. After the system image buffer association list 1154 has been created, virtual adapter 1112 validates whether each DMA write or DMA read requested by system image 1116 is contained within a buffer in system image buffer association list 1154. If the DMA write or DMA read requested by system image 1116 is contained within a buffer in the system image buffer association list 1154, then virtual adapter 1112 may perform the operation. Otherwise, virtual adapter 1112 is prohibited from performing the operation. Alternatively, the PCI family adapter 1101 may use a special, LPAR manager-style virtual adapter (rather than virtual adapter 1112) to perform the check that determines if DMA write or DMA read operations requested by system image 1116 is contained within a buffer in the system image buffer association list 1154. In a similar manner, virtual adapter 1104 associated with system image 1108 may validate DMA write or read requests submitted by system image 1108. Particularly, virtual adapter 1104 provides validation for DMA read and write requests from system image 1108 by determining whether the DMA write or read requested by system image 1108 is contained within a buffer in a buffer association list that contains PCI bus starting and ending address pairs in association with system image buffer starting and ending address pairs of buffers allocated to system image 1108 in a manner similar to that described above for system image 1116 and virtual adapter 1112.

The fourth mechanism that LPAR manager 708 can use to associate and make available host memory to a system image and to one or more virtual adapters is to write into the virtual adapter's resources a single starting and ending address in system image buffer association list 1154. In this implementation, virtual adapter resources 1150 contains a single pair of PCI bus starting and ending address that is associated by the platform hardware to a pair (starting and ending) of addresses associated with a system image buffer, such as SI 2 Buffer 1 1166. At initial configuration, and during reconfigurations, LPAR manager 708 loads the starting and ending addresses of SI 2 buffer 1 1166 into the system image buffer association list 1154 in virtual adapter resources 1150. The system image buffer association list 1154 then defines the set of addresses that virtual adapter 1112 can use in DMA write and read operations. After the system image buffer association list 1154 has been created, virtual adapter 1112 validates whether each DMA write or DMA read requested by system image 1116 is contained within the system image buffer association list 1154. If the DMA write or DMA read requested by system image 1116 is contained within system image buffer association list 1154, then virtual adapter 1112 may perform the operation. Otherwise, virtual adapter 1112 is prohibited from performing the operation. Alternatively, the PCI family adapter 1101 may use a special, LPAR manager-style virtual adapter (rather than virtual adapter 1150) to perform the check that determines if DMA write or DMA read requested by system image 1116 is contained within a page system image buffer association list 1154. In a similar manner, virtual adapter 1104 associated with system image 1108 may validate DMA write or read requests submitted by system image 1108. Particularly, virtual adapter 1104 provides validation for DMA read and write requests from system image 1108 by determining whether the DMA write or read requested by system image 1108 is contained within a buffer in a buffer association list that contains a single PCI bus starting and ending address in association with a system image buffer starting and ending address allocated to system image 1108 in a manner similar to that described above for system image 1116 and virtual adapter 1112.

Turning next to FIG. 12, a functional block diagram of a PCI family adapter configured with memory addresses that are made accessible to a system image is depicted in accordance with a preferred embodiment of the present invention.

FIG. 12 depicts four different mechanisms by which a LPAR manager can associate PCI family adapter memory to a virtual adapter, such as virtual adapter 1204, and to a system image, such as system image 1208. Once PCI family adapter memory has been associated to a system image and a virtual adapter, the system image can then perform Memory Mapped I/O write and read (i.e., store and load) operations directly to the PCI family adapter memory.

A notable difference between the system image and virtual adapter configuration shown in FIG. 11 and FIG. 12 exists. In the configuration shown in FIG. 11, PCI family adapter 1101 only holds a list of host addresses that do not have any local memory associated with them. If the PCI family adapter supports flow-through traffic, then data arriving on an external port can directly flow through the PCI family adapter and be transferred, through DMA writes, directly into these host addresses. Similarly, if the PCI family adapter supports flow-through traffic, then data from these host addresses can directly flow through the PCI family adapter and be transferred out of an external port. Accordingly, PCI family adapter 1101 shown in FIG. 11 does not include local adapter memory and thus is unable to initiate a DMA operation. On the other hand, PCI family adapter 1201 shown in FIG. 12 has local adapter memory that is associated with the list of host memory addresses. PCI family adapter 1201 can initiate, for example, DMA writes from its local memory to the host memory or DMA reads from the host memory to its local memory. Similarly, the host can initiate, for example, Memory Mapped I/O writes from its local memory to the PCI family adapter memory or Memory Mapped I/O reads from the PCI family adapter memory to the host's local memory.

The first and second mechanisms that LPAR manager 708 can use to associate and make available PCI family adapter memory to a system image and to a virtual adapter is to write into the PCI family adapter's physical adapter memory translation table 1290 a page size and the starting address of one (first mechanism) or more (second mechanism) pages. In this case all pages have the same size. For example, FIG. 12 depicts a set of pages that have been mapped between system image 1208 and virtual adapter 1204. Particularly, SI 1 Page 1 1224 through SI 1 Page N 1242 of system image 1208 are mapped (illustratively shown by interconnected arrows) to virtual adapter memory pages 1224-1232 of physical adapter 1201 local memory. For system image 1208, all associated pages 1224-1242 in the list have the same size. At initial configuration, and during reconfigurations, LPAR manager 708 loads the PCI family adapter's physical adapter memory translation table 1290 with the page size and the starting address of one or more pages. The physical adapter memory translation table 1290 then defines the set of addresses that virtual adapter 1204 can use in DMA write and read operations. After physical adapter memory translation table 1290 has been created, PCI family adapter 1201 (or virtual adapter 1204) validates that each DMA write or DMA read requested by system image 1208 is contained in the physical adapter memory translation table 1290 and is associated with virtual adapter 1204. If the DMA write or DMA read requested by system image 1208 is contained in the physical adapter memory translation table 1290 and is associated with virtual adapter 1204, then virtual adapter 1204 may perform the operation. Otherwise, virtual adapter 1204 is prohibited from performing the operation. The physical adapter memory translation table 1290 also defines the set of addresses that system image 1208 can use in Memory Mapped I/O (MMIO) write and read operations. After physical adapter memory translation table 1290 has been created, PCI family adapter 1201 (or virtual adapter 1204) validates whether the Memory Mapped I/O write or read requested by system image 1208 is contained in the physical adapter memory translation table 1290 and is associated with virtual adapter 1204. If the MMIO write or MMIO read requested by system image 1208 is contained in the physical adapter memory translation table 1290 associated with virtual adapter 1204, then virtual adapter 1204 may perform the operation. Otherwise virtual adapter 1204 is prohibited from performing the operation. It should be understood that in the present example, other system images and associated virtual adapters, e.g., system image 1216 and virtual adapter 1212, are configured in a similar manner for PCI family adapter 1201 (or virtual adapter 1212) validation of DMA operations and MMIO operations requested by system image 1216.

The third and fourth mechanisms that LPAR manager 708 can use to associate and make available PCI family adapter memory to a system image and to a virtual adapter is to write into the PCI family adapter's physical adapter memory translation table 1290 one (third mechanism) or more (fourth mechanism) buffer starting and ending addresses (or starting address and length). In this case, the buffers may have different sizes. For example, FIG. 12 depicts a set of varying sized buffers that have been mapped between system image 1216 and virtual adapter 1212. Particularly, SI 2 Buffer 1 1244 through SI 2 Buffer N 1248 of system image 1216 are mapped to virtual adapter buffers 1258-1274 of virtual adapter 1212. For system image 1216, the buffers in the list have different sizes. At initial configuration, and during reconfigurations, LPAR manager 708 loads the PCI family adapter's physical adapter memory translation table 1290 with the starting and ending address (or starting address and length) of one or more pages. The physical adapter memory translation table 1290 then defines the set of addresses that virtual adapter 1212 can use in DMA write and read operations. After physical adapter memory translation table 1290 has been created, PCI family adapter 1201 (or virtual adapter 1212) validates that each DMA write or DMA read requested by system image 1216 is contained in the physical adapter memory translation table 1290 and is associated with virtual adapter 1212. If the DMA write or DMA read requested by system image 1216 is contained in the physical adapter memory translation table 1290 and is associated with virtual adapter 1212, then virtual adapter 1212 may perform the operation. Otherwise, virtual adapter 1212 is prohibited from performing the operation. The physical adapter memory translation table 1290 also defines the set of addresses that system image 1216 can use in Memory Mapped I/O (MMIO) write and read operations. After physical adapter memory translation table 1290 has been created, PCI family adapter 1201 (or virtual adapter 1212) validates whether a MMIO write or read requested by system image 1216 is contained in the physical adapter memory translation table 1290 and is associated with virtual adapter 1212. If the MMIO write or MMIO read requested by system image 1216 is contained in the physical adapter memory translation table 1290 and is associated with virtual adapter 1212, then virtual adapter 1212 may perform the operation. Otherwise virtual adapter 1212 is prohibited from performing the operation. It should be understood that in the present example, other system images and associated virtual adapters, e.g., system image 1208 and associated virtual adapter 1204, are configured in a similar manner for PCI family adapter 1201 (or virtual adapter 1204) validation of DMA operations and MMIO operations requested by system image 1216.

With reference next to FIG. 13, a functional block diagram of a PCI family adapter and a physical address memory translation table, such as a buffer table or a page table, is depicted in accordance with a preferred embodiment of the present invention.

FIG. 13 also depicts four mechanisms for how an address referenced in an incoming PCI bus transaction 1304 can be used to look up the virtual adapter resources (including the local PCI family adapter memory address that has been mapped to the host address), such as virtual adapter resources 1394 or 1398, associated with the memory address.

The first mechanism is to compare the memory address of incoming PCI bus transaction 1304 with each row of high address cell 1316 and low address cell 1320 in buffer table 1390. High address cell 1316 and low address cell 1320 respectively define an upper and lower address of a range of addresses associated with a corresponding virtual or physical adapter identified in association cell 1324. If incoming PCI bus transaction 1304 has an address that is lower than the contents of high address cell 1316 and that is higher than the contents of low address cell 1320, then incoming PCI bus transaction 1304 is within the high address and low address cells that are associated with the corresponding virtual adapter identified in association cell 1324. In such a scenario, the incoming PCI bus transaction 1304 is allowed to be performed on the matching virtual adapter. Alternatively, if incoming PCI bus transaction 1304 has an address that is not between the contents of high address cell 1316 and the contents of low address cell 1320, then completion or processing of incoming PCI bus transaction 1304 is prohibited. The second mechanism is to simply allow a single entry in buffer table 1390 per virtual adapter.

The third mechanism is to compare the memory address of incoming PCI bus transaction 1304 with each row of page starting address cell 1322 and with each row of page starting address cell 1322 plus the page size in page table 1392. If incoming PCI bus transaction 1304 has an address that is higher than or equal to the contents of page starting address cell 1322 and lower than page starting address cell 1322 plus the page size, then incoming PCI bus transaction 1304 is within a page that is associated with a virtual adapter. Accordingly, incoming PCI bus transaction 1304 is allowed to be performed on the matching virtual adapter. Alternatively, if incoming PCI bus transaction 1304 has an address that is not within the contents of page starting address cell 1322 and page starting address cell 1322 plus the page size, then completion of incoming PCI bus transaction 1304 is prohibited. The fourth mechanism is to simply allow a single entry in page table 1392 per virtual adapter.

With reference next to FIG. 14, a functional block diagram of a PCI family adapter and a physical address memory translation table, such as a buffer table, a page table, or an indirect local address table, is depicted in accordance with a preferred embodiment of the present invention.

FIG. 14 also depicts several mechanisms for how a requestor bus number, such as host bus number 1408, a requestor device number, such as host device number 1412, and a requestor function number, such as host function number 1416, referenced in incoming PCI bus transaction 1404 can be used to index into either buffer table 1498, page table 1494, or indirect local address table 1464. Buffer table 1498 is representative of buffer table 1390 shown in FIG. 13. Page table 1490 is representative of page table 1392 shown in FIG. 13. Local address table 1464 contains a local PCI family adapter memory address that references either a buffer table, such as buffer table 1438, or a page table, such as page table 1434, that only contains host memory addresses that are mapped to the same virtual adapter.

The requestor bus number, such as host bus number 1408, requestor device number, such as host device number 1412, and requester function number, such as host function number 1416, referenced in incoming PCI bus transaction 1404 provides an additional check beyond the memory address mappings that were set up by a host LPAR manager.

Turning next to FIG. 15, a virtual adapter level management approach is depicted in accordance with a preferred embodiment of the present invention. Under this approach, a physical or virtual host creates one or more virtual adapters, such as virtual adapter 1514, that each contain a set of resources within the scope of the physical adapter, such as PCI adapter 1532. Each virtual adapter is associated with a host side system image. A virtual adapter comprises a collection of resources (either virtualized or partitioned) of the physical adapter. By defining a virtual adapter entity, all virtual resources associated with a system image can be collectively manipulated by directing an action to the corresponding virtual adapter. For example, a virtual adapter (and all included virtual resources) can be created, destroyed, or modified by performing a function targeting the corresponding virtual adapter. Additionally, the virtual adapter management approach allows all resources of a virtual adapter to be identified with a single identifier, e.g., a bus, device, and function number, that is associated with the virtual adapter. The set of resources associated with virtual adapter 1514 may include, for example: processing queues and associated resources 1504, PCI port 1528 for each PCI physical port on PCI adapter 1532, a PCI virtual port 1506 that is associated with one of the possible addresses on adapter PCI port 1528, one or more downstream physical ports 1518 and 1522 for each downstream physical port on PCI adapter 1532, downstream virtual port 1508 and 1510 that is respectively associated with one of the possible addresses on physical port 1518 and 1522, and one or more address translation and protection tables (ATPTS) 1512.

Turning next to FIG. 16, a virtual resource level management approach is depicted in accordance with a preferred embodiment of the present invention. Under this approach, a physical or virtual host creates one or more virtual resources on physical adapter 1674, such as a processing queue 1694, a virtual PCI port 1692 that is associated with one of the possible addresses on adapter PCI port 1678, a virtual downstream ports 1688 and 1690 that is respectively associated with one of the possible addresses on physical ports 1680 and 1684, and a memory translation and protection table (ATPT) 1676. The virtual resource level management approach is distinguished from the virtual adapter level management approach in that virtual resources are manipulated and identified individually. For example, a collection of virtual resources may be individually created and associated with a host side system image. Each virtual resource associated with a system image has a respective identifier, such as a bus, device, and function number. A manipulation of a virtual resource is performed independently of other virtual resources. Thus, for example, a set of virtual resource creation functions may be performed to create a set of virtual resources that are associated with a system image. No construct or container entity collectively defines a set of virtual resources in the virtual resource level management approach.

Turning next to FIG. 17, Quality of Service (QoS) resources used by the host and adapter to associate a quality of service level to one or more virtual I/O adapters or virtual resources that reside within a physical adapter, such as a PCI, PCI-X, or PCI-E adapter, are depicted in accordance with a preferred embodiment of the present invention. Under this approach, a super-privileged resource 1790, such as a Hypervisor, maintains a QoS table 1798 containing QoS settings for virtual adapters (or virtual resources) assigned to each SI in the system. For a PCI adapter that uses the virtual adapter level management approach, each virtual adapter has one entry in QoS table 1798 that describes that virtual adapter's QoS settings (and thus the SI to which the virtual adapter is assigned). For a PCI adapter that uses the virtual resource level management approach, each set of virtual resources assigned to a single system image has one entry in the QoS table that describes that set of virtual resources' QoS settings. The super-privileged resource 1790, such as a Hypervisor, may also have backing store 1794 to hold QoS segment pointer context. Also, for each SI, the super-privileged resource 1790, such as a Hypervisor, sets the system image's QoS level in the adapter's SI QoS level weights 1762 by setting the level weights in a quality of service table segment.

In the illustrative example, two SIs 1712 and 1713 are shown as allocated in the logically partitioned data processing system. Each system image maintains a respective QoS table containing QoS settings for processing queues owned by that particular system image. For example, system image 1712 maintains QoS table 1748 containing QoS settings for processing queues owned by system image 1712, and system image 1713 maintains QoS table 1749 containing QoS settings for processing queues owned by system image 1713. System images 1712 and 1713 may also have a backing store, e.g., system image's 1712 backing store 1744 to store processing queue (PQ) context.

The PCI adapter, such as adapter 1720, contains a QoS table segment, such as quality of service (QoS) table segment 1728. The first entry in QoS table segment 1728 contains a pointer to a next QoS table segment, such as QoS table segment 1729 used to maintain additional SI QoS level weights in the event the capacity of QoS table segment 1728 is consumed. Each of the other entries in the QoS table segment 1728 contains QoS settings associated with a particular system image. As referred to herein, a QoS setting for an SI (referred to herein as an SI level weight) is a numerical or other identifier that defines a precedence for processing I/O transactions associated with the SI. For example, a QoS setting for an SI may be implemented as an SI level weight comprising an integer value of a predefined integer set, such as SI level weight value of “1” through “5” with an SI level weight value of “1” defining the highest QoS setting available to be assigned to an SI, and an SI level weight value of “5” defining the lowest QoS setting available to be assigned to an SI. Each QoS setting of an SI maintained in one of QoS table segment entries 1728 b-1728 n is uniquely associated with a system image and with a PQ table segment assigned to the system image. For illustrative purposes, assume entry 1728 b is associated with SI 1712 and contains an SI level weight of “1”. Further assume that entry 1728 b is associated with SI 1713 and contains an SI level weight of “2”. Thus, SI 1712 having a quality of service level “1” is provided higher processing precedence than SI 1713 having a quality of service level “2”.

In accordance with a preferred embodiment of the present invention, each system image contains a PQ table segment assigned thereto that defines QoS levels of each processing queue assigned to the system image. In the illustrative example, PQ table segment 1700 is assigned to SI 1712, and PQ table segment 1701 is assigned to SI 1713. Entries in a PQ table segment define (or reference) QoS levels of each PQ allocated to the system image to which the PQ table segment is assigned. Additionally, an entry of a PQ table segment may be used to reference another PQ table segment to facilitate processing of I/O operations according to QoS levels as described more fully below.

In the illustrative example, the first entry in each processing queue table segment contains a pointer to the next processing queue table segment. For example, entry 1700 a of PQ table segment 1700 assigned to SI 1712 contains a pointer to PQ table segment 1701 assigned to SI 1713. Each of the other entries in a PQ table segment contains (or alternatively references) PQ context including PQ QoS values. For example, each of entries 1700 b-1700 o in processing queue table segment 1700 assigned to SI 1712 contains context and a PQ QoS value of a particular processing queue associated with SI 1712 or a reference to such context and PQ QoS data for a processing queue associated with the entry. In the illustrative example, SI 1712 has N processing queues allocated thereto, and each of entries 1700 b-1700 o contain (or reference) context and a QoS level of one of the PQs. For example, entry 1700 o contains a reference to context 1758 associated with processing queue N allocated to SI 1712 and includes a QoS setting (or PQ QoS level weight) of processing queue N. Alternatively, entry 1700 o may contain a pointer to the context and QoS setting for PQ N. In the illustrative example, PQ N has a PQ QoS level weight of “5.” In a similar manner, each of PQs 1-3 allocated to SI 1712 have PQ QoS level weights of “1”, “2”, and “1,” respectively. Also, for each PQ, the system image sets the processing queue's QoS level in the adapter's PQ QoS level weights 1766 (that is, the PQ QoS level weights in the PQ table segment allocated to the system image. A system image is restricted from accessing a PQ table segment assigned to other system images such that a given system image can only set PQ QoS level weights to PQs assigned to the particular system image.

Thus, QoS table segment 1728 provides a mechanism for defining QoS level service assignments to system images allocated in a logically partitioned data processing system. The SI level weights maintained by QoS table segment 1728 define QoS settings that specify a processing precedence afforded SIs. Additionally, a PQ table segment respectively assigned to each individual SI defines PQ level weights that establish a processing precedence of PQs allocated to an SI once the SI is selected for processing.

With reference next to FIG. 18, a flowchart outlining an exemplary operation of the association of a quality of service level to one or more system images and its associated virtual I/O adapters or virtual resources that reside within a physical adapter, such as a PCI, PCI-X, or PCI-E adapter, in accordance with a preferred embodiment of the present invention is depicted.

Through either a user management interface or an automated script/workflow, a request to assign QoS levels to a set of system images and their associated virtual adapters (if the PCI adapter uses virtual adapter level resource management) or virtual resources (if the PCI adapter uses virtual resource level management) is invoked (step 1800).

The super-privileged resource directly, or through an intermediary, checks to see if the PCI adapter has sufficient resources to complete the request (step 1804). The super-privileged resource may, for example, be the LPAR manager, such as LPAR manager 708 shown in FIG. 7. If the PCI adapter doesn't have sufficient resources, then the super-privileged resource generates an error result for the operation (step 1812), and the super-privileged resource then returns the error results (step 1824).

Returning again to step 1804, if the super-privileged resource determines the physical adapter has sufficient resources to complete the request, the super-privileged resource then directly, or through an intermediary, assigns QoS levels to a set of SIs by updating, for each SI, the QoS table segments associated with the virtual resources allocated to the particular SI (step 1816). For example, the super-privileged resource may write an SI level weight to entry 1728 b of “1” to define the QoS setting assigned to SI 1712, and may write an SI level weight to entry 1728 b of “2” to define the QoS setting assigned to SI 1713. Once each SI has an SI level weight written to the QoS table segment, the super-privileged resource directly, or through an intermediary, then returns a successful completion result for the operation according to step 1824.

With reference next to FIG. 19, a flowchart outlining an exemplary operation of the association of a quality of service level to one or more virtual resources, such as processing queues, owned by a system image and residing within a physical adapter, such as a PCI, PCI-X, or PCI-E adapter, in accordance with a preferred embodiment of the present invention is depicted.

Through either a user management interface or an automated script/workflow, a request to assign QoS levels to a set of processing queues that have been assigned to a specific system image is invoked (step 1900).

The system image or other privileged resource checks to see if the processing queues actually exist (step 1904). If the resources do not exist, then the system image returns an error result for the operation (step 1924).

Returning again to step 1904, if the privileged resource determines that the resources do exist, the privileged resource then directly, or through an intermediary, assigns QoS levels to the set of processing queues by updating, for each processing queue, the processing queue's QoS settings field (or fields) in the processing queue's context table (step 1916). For example, system image 1712 may update QoS settings for each processing queue allocated to system image 1712 by writing PQ QoS level weights to each entry 1700 b-1700 o respectively associated with a PQ allocated to SI 1712. The system image then returns a successful completion result for the operation according to step 1916.

With reference next to FIG. 20, a flowchart outlining an exemplary operation of outbound transfers that use quality of service level differentiation of virtual I/O adapters or virtual resources that reside within a physical adapter, such as a PCI, PCI-X, or PCI-E adapter, in accordance with a preferred embodiment of the present invention is depicted.

The routine is entered when the adapter's outbound transmit queue is empty, the adapter's link layer is ready to accept another transmit request, and the adapter has set a “ready to transmit frame” indicator in the SI QoS level weight table, e.g., QoS table segment 1728 shown in FIG. 17, for a processing queue that has a frame ready for transmission (step 2000). The adapter uses the SI QoS level weight to select the next SI to process.

The adapter reads the next super-privileged QoS table entry to determine which processing queue segment to process next (step 2004). On an initial evaluation, that is on a first evaluation after the QoS table segment has been initialized, the adapter preferably begins by reading QoS table segment 1728 for an entry identifying an SI with the highest SI level weight, e.g., an entry with an SI level weight of “1.” On subsequent evaluations, the adapter performs this function by starting at the last entry that was checked and continuing through the set of entries within the same QoS table segment as the last entry that was checked until it reaches the end of the QoS Table Segment. Once a given QoS table segment is fully traversed, the adapter uses the QoS table segment pointer (first entry in the table) to go on to the next QoS table segment that is at the same SI QoS level. Once all QoS table segments that are at the same QoS level have been traversed, the adapter proceeds to the next QoS table segment pointed to by the first entry in the current QoS table segment and repeats until it reaches a processing queue segment that has an outbound queue ready to transmit.

The adapter then reads the next PQ table segment to determine which processing queue to process next (step 2012). The adapter retrieves the next outbound transmit frame by using the processing queue's work queue element (WQE) header to retrieve the processing queue's WQE and passes the next frame to be transmitted in sequence to the adapter's outbound transmit queue. The adapter then returns to step 2000.

Embodiments of the present invention provide a mechanism by which a single physical I/O adapter, such as a PCI, PCI-X, or PCI-E adapter, can associate one or more virtual I/O adapters or virtual resources to a quality of service level. Quality of service differentiation is provided to system images by associating quality of service level weights to system images allocated in a logically partitioned data processing system. A system image assigns quality of service level weights to processing queues allocated to the system image. Thus, quality of service differentiation is provided on a per-system image basis by providing processing precedence to system images with higher quality of service level weights relative to other system images with lower quality of service level weights. Moreover, quality of service differentiation is provided on a per-processing queue basis by providing processing precedence to processing queues with higher quality of service level weights relative to processing queues with lower quality of service level weights.

The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. 

1. A method of providing quality of service differentiation to system images in a logically partitioned data processing system, the method comprising the computer implemented steps of: respectively associating a quality of service system image level value to each of a plurality of system images; respectively associating a processing queue quality of service level weight to one or more processing queues respectively allocated to each of the plurality of system images; and responsive to respectively associating the quality of service system image level value to each of the plurality of system images and the processing queue quality of service level weight to the one or more processing queues allocated to the plurality of system images, providing processing precedence of input/output operations according to at least one of the quality of service system image level value and the processing queue quality of service level weight.
 2. The method of claim 1, wherein a super-privileged resource associates a respective quality of service system image level value to each of the plurality of system images.
 3. The method of claim 1, wherein each of the plurality of system images respectively associates a processing queue service level weight to the one of more processing queues allocated thereto.
 4. The method of claim 1, wherein providing processing precedence of input/output operations further comprises: selecting a first system image of the plurality of system images; and evaluating an outbound queue allocated to the first system image.
 5. The method of claim 4, further comprising: responsive to determining the outbound queue allocated to the first system image does not have data ready to transmit, selecting a second system image of the plurality of system images, wherein the second system image has a quality of service system image level value associated therewith that is less than a quality of service system image level value associated with the first system image.
 6. The method of claim 4, wherein the first system image has a plurality of processing queues allocated thereto and each of the plurality of processing queues has a respective processing queue quality of service level weight associated therewith, the method further comprising: selecting a first processing queue of the plurality of processing queues associated with the first system image; and evaluating the first processing queue to determine if it has data ready to transmit.
 7. The method of claim 7, further comprising: responsive to determining the first processing queue does not have data ready to transmit, selecting a second processing queue of the plurality of processing queues associated with the first system image, wherein the second processing queue has a processing queue quality of service level weight less than a processing queue quality of service level weight of the first processing queue; and evaluating the second processing queue to determine if it has data ready to transmit.
 8. A computer program product in a computer readable medium for providing quality of service differentiation to system images in a logically partitioned data processing system, the computer program product comprising: first instructions that respectively associate a quality of service system image level value to each of a plurality of system images; second instructions that respectively associate a processing queue quality of service level weight to one or more processing queues respectively allocated to each of the plurality of system images; and third instructions that, responsive to the first instructions respectively associating the quality of service system image level value to each of the plurality of system images and the second instructions associating the processing queue quality of service level weight to the one or more processing queues allocated to the plurality of system images, provide processing precedence of input/output operations according to at least one of the quality of service system image level value and the processing queue quality of service level weight.
 9. The computer program product of claim 8, wherein the first instructions are implemented in a super-privileged resource.
 10. The computer program product of claim 8, wherein the second instructions are implemented in each of the plurality of system images.
 11. The computer program product of claim 8, wherein the third instructions further comprise: fourth instructions that select a first system image of the plurality of system images; and fifth instructions that evaluate an outbound queue allocated to the first system image.
 12. The computer program product of claim 11, further comprising: sixth instructions that, responsive to the fifth instructions determining the outbound queue allocated to the first system image does not have data ready to transmit, select a second system image of the plurality of system images, wherein the second system image has a quality of service system image level value associated therewith that is less than a quality of service system image level value associated with the first system image.
 13. The computer program product of claim 11, wherein the first system image has a plurality of processing queues allocated thereto and each of the plurality of processing queues has a respective processing queue quality of service level weight associated therewith, the computer program product further comprising: sixth instructions that select a first processing queue of the plurality of processing queues associated with the first system image; and seventh instructions that evaluate the first processing queue to determine if it has data ready to transmit.
 14. The computer program product of claim 13, further comprising: eighth instructions that, responsive to the seventh instructions determining the first processing queue does not have data ready to transmit, select a second processing queue of the plurality of processing queues associated with the first system image, wherein the second processing queue has a processing queue quality of service level weight less than a processing queue quality of service level weight of the first processing queue; and ninth instructions that evaluate the second processing queue to determine if it has data ready to transmit.
 15. A logically partitioned data processing system adapted to provide quality of service differentiation to system images, comprising: a physical adapter having adapter resources; a memory that contains the plurality of system images; and a processor that, responsive to execution of a set of instructions, respectively associates a quality of service system image level value to each of the plurality of system images, respectively associates a processing queue quality of service level weight to one or more processing queues respectively allocated to each of the plurality of system images, and provides processing precedence of input/output operations according to at least one of the quality of service system image level value and the processing queue quality of service level weight.
 16. The data processing system of claim 15, further comprising: a super-privileged resource that comprises a subset of the set of instructions, wherein the subset of the set of instructions, when executed by the processor, associate a respective quality of service system image level value to each of the plurality of system images.
 17. The data processing system of claim 15, wherein each of the plurality of system images respectively comprise a subset of the set of instructions, wherein the subset of the set of instructions, when executed by the processor, associate a processing queue service level weight to one of more processing queues.
 18. The data processing queue of claim 15, wherein the processor provides processing precedence of input/output operations by selecting a first system image of the plurality of system images, and evaluates an outbound queue allocated to the first system image.
 19. The data processing system of claim 18, wherein the processor, responsive to determining the outbound queue allocated to the first system image does not have data ready to transmit, selects a second system image of the plurality of system images, wherein the second system image has a quality of service system image level value associated therewith that is less than a quality of service system image level value associated with the first system image.
 20. The data processing system of claim 19, wherein the first system image has a plurality of processing queues allocated thereto and each of the plurality of processing queues has a respective processing queue quality of service level weight associated therewith, and wherein the processor selects a first processing queue of the plurality of processing queues associated with the first system image, and evaluates the first processing queue to determine if it has data ready to transmit. 